Method of regulating motors



m1. 860,066. I Patented Oct. 16, 1900. F. J. SPRAGUE.

METHOD or REGULATING moro'ns.

(IuIoieL) I 7 z Sheen-Sheet 1.-

. I, Witne 559s: Inventor,

W K Frank [L5 '29"; .f M y fl No. 660,066. mama Oct. I6, 1900.

' r. a. SPRAGUE.

METHOD OF REGULAHNG RDTORS.

In Nodal.) 2 Sheets-Sheet 2.

Witnes se 9 Inventor,

WWW/ 17 V Frank pragug UNITED STATES PATENT OFFICE.

FRANK SPBAGUE,, OF NEW YORK, N. Y., ASSIGNOR TO THE SPRAGUE ELECTRIC COMPANY, or, new JERSEY.

M ETHoo OF ssouts'rmo Morons.

srscmca'rron forming part of Letters ram; No. 660,066. dated October 16, 1960. i Original lpplicstiou filed April so, 1398, sis-1 No. 579.239. 13mm a mapplication filed hit as, 1900. sum it. g 21,341. on model.

To all whom it may concern.-

Be it known that I, FRANK. J. SPRAGUE, a citizen of the United States of America, and a resident of the city of New York, borough of Manhattan, in the county of New York and State of New York, have invented certain new and useful Improvements in Methods of Regulating Motors, (for which I have received foreign patents in France, No. 278,105, dated May 20, 1898, and in GreatBritain, No. 11,158, dated May 16,1898, and have filed an application in Germany, dated May 24,1898) of which the following is a specification.

This application is filed by way of division of my former application for improvements in traction systems, Serial No. 679,239, filed April 30, 1898. The system is fully illustrated and described in my British patent, No. 11,158, of May 16, 1898.

In my earlier application there is set forth what I have called a multiple-unit system of operating railways. A characteristic feature of the multiple-unit system is that each fully-equipped car is auuit and that a train made up of such cars is a unit havingall ofthe characteristics of the car without any limitations being imposed as to the number, or der, or end relation of the cars going to make up the train. Of course a train can be made up of cars equipped with motors and'cars not equipped with motors, but provided with the train-line and connections for transmitting control, and the train be controlled from any one of a number of points. In accordance with this system the motors distributed on the cars going to make up the train or part ofa train are controlled from one or more selected points by an operators or masters switch or controller, the controllers individual to the motor equipments being operated through a train-line and appropriate connections. Some method must be adopted which will insure that different motors,with'- in practical limits, will do their proportionate amount of work, be limited in the amount of current which they can each take, be saved from undue rapidity of current increment, and generally operate to properly regulate and proportion the current in the motors. The method consists in regulating the operation of thecontroller for any motor or motor equipment constituting part of a system of motors or motor equipments all under common control or working on a common load, or, as here shown, both under common control and working on a common load, by auto matically varying the operation of the controller for that motor or motor equipment under the influence of thecurrent in theinotor'or motors comprised in that equipment. Thus if the controller of oue motor starts ahead more rapidly than the others, or if it operates more rapidly, or if there are differences in the field strength, so that one motor or motorequipment will get more current than another in excess of the predetermined limit of safety or-desirability, or if for any reason, normal or abnormal, there is an excess of currentthrough one controller, such as might occur if some part of a circuit were grounded or were disarranged, thus threatening the controller or circuits with damage,

the throttle connected with the controller of that particular motor or motor equipment will stop the progression of that controller until by reason of the speeding up of the train under the driving of the other motors the current through the motor or motor equip" ment in question falls to the predetermined limit. The throttle will then close and normal conditions be reestablished, or if the controller unchecked can operate more quickly than the motor can safely take current then the throttle will check the progression of the controller. The throttle does not operate on the movement of the controller toward open position.

In the accompanying drawings, which form a part of this specification, Figure 1 is a disgrammatic representation of a complete oar system with a portion of the train-line'outwo other cars. Fig. 2 is a diagrammatic repro sentation of two connected car systems, show ing the operation of the throttle. what simpler than the system shown in'Fig. 1. Fig. l is taken from my earlier application above referred to. It is Fig. 11 and a part of Fig. 22 of that application combined, without change, except that some of the reference-letters are difieren-t.

The general arrangement shown in Fig. 1

It is some comprises a pair of motors on each of the cars,

seeded operated in accordance with what is known as the series-multiple control, which is a convenient, but not an essential, method. This is effected through a current varying controller consisting of a series-multiple switch anda rheost-at. The combined-seriesmnltiple switch and rheostat, together with certain pilot-motor circuit-interrupter contacls, to be hereinafter described, are all combined on a single cylinder called the control-. ler-block and-will be referred to collectively as the main switchl Reversal is effected through a separate reverser-switch. In case of emergency the current can be instantly cut ofi at the reverser without waiting for the current-varying controller to come to open position. The current-varying controller is operated in both directions by a double-field pilot-motorthrough a set of relays, which are in turn 'operated'from the operators switch or master-controller. The reverser is operated directly by solenoids connected with the operators switch and is spring-retracted.

There are preferably two ope rators switches or master-controllers, one located on each platform, like contacts of the two being con nected by wires constituting an operatorsswitch cable.

. The various car systems are connected with the train-lines in multiple relation with each other, as indicated in Fig. 1. In this figure an entirecar system and the section of the train-line located upon one of the cars are shown, together with a part of the sections of thetrain-line located upon two other cars. In order to complete the diagram, it would only be necessary to add for the other two cars an exact. duplication of the car system shown in the figure and to connect these two car systems to the train-line in the manner shown. p y

Each operators switch is provided with reverser or directional contacts and speed-contacts; The reverser-contact's a b are so placed that when the handle P is moved from the open position the switch is always closed at one or the other of these contacts. Vires ab, forming part of a reverser-circnit, lead from these contacts on each switch tnraugh a circuit-opener 1 and through two coils a b of solenoids which form part of the reverser.

Beyond the solenoids the two wires are unitedand are carried to a resistance 2 or, after the reverser operates, to contacts 3 on "the reveiser. Thence the circuit is through a circult-opener 4, through an overload safety-circuit opener 5, through the solenoid of an autolnatic safety reverserrelay 6, through a cut-out switch Z- on the controller-block, and thence to ground at G. The solenoid 6 draws up its plunger, opening the lower set of contacts controlled by it and closing the two upper sets of contacts controlled by it. Through one set of these contacts 7 a branch to ground is closed around the cutout switch 7. So long as the operators switch is closed on one side the reverser is held in position to condescribed with reference to Fig. 1.

nect the armatures of the driving-motors up to the source of supply in one direction, and

so long as it is closed on the other side the reverser is held in position to connect the armatur'es of the driving-motors up to the source of supplyin the other direction. The fields of these motors are not reversed. As soon as the platform-switch is opened the reverser opens the main motor-circuit without regard to the position of the main switch and indepen ently thereof under the influence of a centering-spring 8, which is put under tension when the reverser is thrown to either sidetroni the open position. The details of theconstruction and operation of the reverser need not be described.

Each operators switch, in addition to the re'verser-con tacts, is provided with three pairs of contacts for controlling the speed, the twocontacts of each pair being connected together and disposed in corresponding-positious on the two sides of th switch. On closing the switch to either side thereof on one of the first pair of speed-controlling contacts, which will be called hereinafter the coast-con tacts 0, no effect isproduced when the systern is in the normal or initial position, for the circuit, which includes the contacts 0 of the coast-relay 0 is open at the pilot-motor circuit-interrupter c, which forms a part of the main switch. If the operators-switch handle is'carried farther around and brought into contact with one of the second or intermediate pair of speed-controlling contacts, which will be called hereinafter the series contacts 3, the corresponding, speed-relay s on each of the cars is energized. The series relay-contacts s on all of the cars are thus closed and the pilot-motors a e each connected in parallel to the line in circuit through a contact controlled by the solenoid of the throttle, above referred to, to be hereinafter fully traced.v When the operators switch is closed on one of the third pair of speed-contacts m, called the multiple contacts, the correspondingv speed-relay 'm. is

energized. The multiple relay-contacts "m on all of the cars are thus closed, and the pilotmotors are each connected to the line in circuit through contacts controlled by the throttle, as will be hereinafter shown. As the operation of this throttle is the basis of the method claimed,the circuit will be completely It is the It is substantially the The circuit through the same on each car. same for Fig. 2.

contacts controlled by the throttle when the series contacts are closed is from the trolley L through the solenoid 9 of an overload safety, through a circuit-opener 10, through the brake-magnet 11 of the pilot'mot'or, through the armature 12 and a field-coil 13 of the pilot-motor, through contacts 14, controlled by the throttle, through contacts 15, controlled by the solenoid 6 of an automatic safety-reverser for the pilot-motor, through contacts 16 17 of the pilot-motor circuit-inacetone 3 terrupter, and'throngh the relay-contacts s to ground at G. When in a similar manner closure of the operators switch at the multiple contact an energizes the corresponding set of multiple speed-relays m closes their contacts m and causes operation of the pilot-motors and main switclnthe circuit is as follows: from the trolley L to the overloadsolenoid9, through the circuitropener 10, through the brake-magnet ll of the pilot-mowr, throughthe field-coil 13 of the pilotmotor, through contacts 14, controlled by the throttle, through the contacts 15, controlled by the automatic safety-reverser, all as before, thence through contacts 16 18 of the pilotmotor circuitinterrupter on the main switch and through relay-contacts m to ground at G. The circuits closed on the return movement of the controller are easily traced. They include the other field-coil 13 of the pilot-motor, which is oppositely wound from the one above mentioned. They do not include the contacts controlled by the throttle. \Vhen by opening theoperators switch or by failure of the line or for any other reason the circuitis opened, the plunger ofsolenoid 6 drops, opening contacts and 7 and closing contacts 19 of the automatic safetyreverser on each car. This causes all of the controllers to return to open-circuit position. "When the cut--outswitch-contacts of the main switch are closed, control of the movement of the main switch is again restored to the operators switch.

It is not necessary to describe more fully the operation of the controller on return to open-circuit position, as this will be clear from the drawings and is not directly involved with the operation of the throttle, which does not come into play during the return movement.

The circuit through the solenoid of the throttle is from the trolley L through the overload-solenoid 9, througha circuit-opener '20 and a blow-out magnet 21, through the rheostat-contacts 22 of the controller, through contacts of a throw-over switch 23 and the coil of the blow-out magnet 24, through re- "arser-contacts 25 and the armature of one of the motorsMf back to reverser-contacts, thence through the field of the motor hi,

- through contacts of the throw-over switch 23,

above referred to, thence through series contacts 26 of the series-multiple switch,through contacts of another throw-over switch 27 and another magnetic blow-ontcoil 28,and through reverser-contacts 29 and the armature of the other motor M to the solenoid 30 of the throttle, thence back to the reverser-contacts, thence through contacts of the second throwover switch 27, above referred to, and thence through the field of the motor M to ground.

When the motors M' M are in multiple, the

solenoid of the throttle is in series with one of the motors only, the circuit being as follows: from the trolley through the overloadsolenoid 9 and the circuit-opener and blowout, through the rheostat-contacts of the controller, thence through two multiple contacts 31 of the-series-multiple switch, thence through the throwover switch 27, the coil of the blow-outmagnet 28, the contacts 29 of the reverser, the armature of motor M, the

solenoid 30 of the throttle, back to the re verser again, through contacts of the throwover switch 27 and the field of the motor M to ground.- The other motor-circuit, which does not include the solenoid of the throttle, can be easily traced through motor M and contacts32toground. If thecurrentihrough the two motors when they are in series or through the motor M when they are in multiple exceeds the predetermined limit, the solenoid 30 of the throttle opens the throttlecontacts 14 in circnitwith the pilot-motor and suspends movement of the main switch until the current drops to the predetermined limit, when the throttle-contacts 14 will be again closed and the main switch will move ahead, provided the circuit has been maintained at the operators switch. If no change has occurred in any other part of the system, the operation of the throttle has no effect excepting to check the advance movement of the controller.

Fig. 2 shows two abutting car s. Only onemotor is shown in each car. The series-par-. alleling feature is omitted throughout the system. A master-controller on the right-hand car is shown as closed to operate the controllers. operated, the controller on the left-hand car being shown somewhat in advance of the other and its operation checked by the opening of the throttle-contacts. Like parts are Both controllers are shown as partially indicated by the same reference-letters as in r Fig. 1, and the circuits can be traced from the foregoing description and are indicated by arrows.

Itwill be seen from the foregoing statement that all the operator has to do when he wants to bring the motors from rest into operation in any arrangement isto close the operators switch at the proper contact. The various controllers will then progress from the open position to the series if the series contact of the operatofsswitch be closed, or to the multip e if the multiple contact of the operators switch be closed, or to the series first and then to the multiple if the series contact of the op-.

eratorsswitch be closed first and held closed and then the multiple contact of the operators switch be closed. It is all a question of the operator permitting the handle to rest long enough on the particular point to bring the controllers to the proper position. Ifthe series or multiple contact. of the ope'rator's switch is opened before the main switch has progressed to the full-series or the full-multiple position, a portion of the resistance of the rheost-at is left in the circuit. when the main switch has reached the full-series or fullmultiple position-thatis, the positions where none of the resistanceo the rheostat is in cir-' cuit-the controller is stopped automatically ing the further increase of current.

by the opening of the pilot-motor circuit at contact 3 if it is to be brought to the full-series position or at contact 172 if it is to be brought to the full-multiple position. On the eturn the circuit is automatically opened at contacts 3 or c and 33. In progressing from open'position' to the full seri'es or full-m ulti pie position the controller is under the control of the throttle, as above explained, which automatically takes care .of the system by stopping or retarding movement of any controller whenever the current in the motor or motor equipment controlled thereby rises beyond the predetermined limit, thus prevent- By thus independently regulating the movement of the main switch on each car the throttle renders'it impossible to overload the driving-motors M M. Simultaneous movement and equal work on each motor equipment are thus insuredwlthout regard to how the operator handles his switch or to the position of any of the controllers at the time the switch is operated.

Theimportance of the throttle will be made further apparent from the following addi tional considerations, among others. The

jcontrollers', even though all made alike, may

. on the different cars.

operate with difierent degrees of promptness, because of differences in the conditions of the bearings and the like arising from use. One controller might start off so much more promptly than the others thatsome motors would get a large current before the others had started. Besides the controllers, the relays on some of the cars might stick or the apparatus otherwise be out of order. Again, car-wheels are allowed to vary ten per cent. in diameter because of the wear of thesteel tires. This variation would not be found on the wheels of asingle truck on any well-organized road, but maybe found on the wheels There may therefore be, for'example, thirty-inch wheels on one car and thirty-three-inch wheels on another car. Again, trains may be made up of cars equipped with motors of different sizes,

' makes, and types having different characcan be effected by a careful motorman withan ampere-meter, watching the current input in a slngleequipment and arresting the movement of the main controller by opening the scenes I I master-controller whenever the current rises to the predetermined limit. In general, with the throttle as I prefer to use it, so long as the current does not reach the predetermined limit set-for safe operation the movement of the controller is independent of the throttle. Since for any specific conditions the characteristics of a' motor can be plotted in terms of current and speed, it may be said that theactivity of the throttle is affected by the speed of'the motor-the less the variation in operation with any given equipmentthe less the throttle is broughtinto play. This automatic response of the throttles to the actual needs of the motors not only affords greater freedom in manipulating the controllers, but insures greater'safety and facility of train operation.

In starting, thethrottle automatically takes care of the rate of acceleration for different loads, stopping the pilot-motor whenever the current 15 too large, and thus insuring quick acceleration of light loads and slower acceleration of heavier loads. Duringthe time of acceleration, also, there may be slight differences in the time of making controller-contacts, and because of these differences the increase of current on the different cars is not absolutely simultaneous, the result in this case being simply that the maximum flux of current required on the train is something less than the aggregate of the maximums on all of the cars, and there would therefore be less disturbance of potential, loss drop on the line, and less sudden changes in demand on the central station. Furthermore, since during the time of acceleration a series-motor operates on a highly-saturated field, and therefore has almost the characteristics of the shunt-motor, if the resistance-divisions are arbitrarily made alikein the controllers on the different cars and changes are made on all cars exactly simultaneously it is quite possible to have differences during acceleration of fully thirty per cent. of the current on different cars. It is true that the resistance, is finally cut out entirely; but the motors then have less-saturated fields, and differences of resistance in the circuit make less differences of current.

I do not limit myself to having the throttle open the pilot-motor circuit directly, for it can equally well'oe made to operate indirectly through the relays controlling the pilot-motor; nor do I limit myself to having the throttie in circuit with one motor only when the two are in multiple, because the throttle can be operated by two coils, one in each motorcircuit, or there can be two throttles, one for each motor-oircuit,controlling-contacts in the pilot-motor or relay-circuits in series with each other; nor do I limit myself to any spescopes a limit myself to having motors forming a motor equipment. It is plain that the throttle I would operate if there were only one motor in each equipment. In my claims I treat each pair of motors as a single motor, the state ment that the motors are connected in multiple or that each motor is supplied with a controller being intended to cover the case of a single motor or of a plurality of motors which may be connected up in series ormultiple or otherwise, as desired;

Generally, I do not limit myself to the details shown, as many changes can be made without departing from the spirit of my invention.

. What I claim, and desire to secure by Let ters Patent of the United States, is-

1. The method of regulating and equalizing the operation of a number of motors in a system, each provided with acontroller,vvhich consists in varying the, operation ofeach of the controllers with the current in the motor controlled therebysubstantially as described.

2. The method of preventing any motor of. asystem of motors connected in multipleeach provided with acontroller, from consuming more than its due proportion of the energy delivered to the system, which consists in check ing the operation of any controller when the current in the motor controlled thereby exceeds a predetermined limit, substantially as described. 3. The method of regulating and equalizing the operation of a number of motors in a system, under common control or working on a common load, and each provided with a controller, which consists in varying the eperation of each of the controllers with the current in the motor controlled thereby, substantially as described.

4. The method of preventing any motor of a system of motors connected in multiple, and

under common control or working on a common load, and each provided with a controller, from consuming more than its due proportion of the energy delivered to the system,- which consists in checking the operation of anycontrollerwhen the currentin the motor controlled thereby exceeds a predetermined limit, substantia ly as described.

5. The method of regulating and prevent ing undue excess'of current in the individual motors or motor equipments of a system under common control, or working on a common load, each motor or motor equipment, being provided with a controller, which con-. sists in varying the operation of each of the controllers with the current in the motor-controlled thereby, substantially as described.

6. The method of governing the operation of each controller of a number of motors in} system in which each motor is providedwith a controller, and all the controllers are governed by a master-controller, which consists in retarding the operation of each of the controllers by the current in the motor controlled thereby, substantially as described.

7. The method of regulating and equalizing the operation of a number of motors in a system under common control and working on a common load, where each motor is provided with a controller, which consists in varying the operation of each of the controllers with the current in the motor controlled thereby, substantially as described.

8. The method of preventing any motor of a system of motors connected in multiple and under common control and working under a' common load, where each is provided witha controller, from consuming more than itsdue proportion of the energy delivered to thesystern, which consists in checking the opera tion of any controller when the current in the motor controlled thereby exceeds the prede-. termined limit, substantially as described.

. Signed by me in New York city, New York; this 22d day of'June, 1900.

FRANK J. SPBAGUBl.

Witnesses: i A. M; Dmmm,

PAULINE STRENGEB- 

